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Feet, joints tied to shoe checks

Tom Jenkyn, an associate professor at the University of Western Ontario, says a lot of the information people get about running shoes and about the type of shoe they require, can't be simply diagnosed by casual observation in a store. (MIKE HENSEN, The London Free Press)

The University of Western Ontario researcher is looking at how the joints in our feet move when we walk.

His work is being used by footwear giants, such as Nike, to study their own shoes. Jenkyn also is looking at whether people who wear orthotics can benefit from his research.

"There's a huge industry out there not just for running shoes, but also for orthotics, but there's not a lot of good evidence as to what they do, whether they're effective and how exactly they work," said Jenkyn, an associate professor of biomechanics in the departments of mechanical engineering and kinesiology.

Jenkyn has developed two ways to measure how joints in the foot move using optical motion capture and x-ray images -- called x-ray fluoroscopy -- where he can watch someone walk in a shoe with orthotics and track what the bones in the foot are doing.

"It sounds simple, but it's really quite difficult to do," said Jenkyn, who got a five-year grant from the National Science and Engineering Research Council, for his work.

His research also is challenging a 15-year belief in the running shoe industry that people fit into one of three groups when they walk or run: neutral, meaning their foot works properly; overpronator, meaning their heel moves out when it hits the ground and the arch collapses; or oversupinator, where the foot is too rigid.

"What my research has shown and what similar researchers . . . have shown is that this isn't the case at all -- that there's a huge amount of variability in how the foot moves, not just between people, but between footsteps," he said.

Jenkyn also came across another interesting discovery: wearing shoes breaks down several of the smaller muscles in the foot, making them weaker.

It's the reason why if you've been walking barefoot all day, your feet hurt because your exercising those smaller muscles that aren't used to being exercised, he said.

One way to strengthen those muscles, he said, is by walking barefoot for some of the day or to tie shoelaces a little looser, allowing the foot to move more in the shoe.

"You're now relying on the muscles of the body itself to give you the strength and stability rather than something you're putting on the foot," he said.

"Usually with orthotics, the idea is if the arch is falling you put an arch support in and support it. This idea goes against that. If the arch is falling it's probably because you need to be exercising those muscles and strengthening up the arch."

Jenkyn's research is studying whether there's a way different orthotics can be used to protect parts of the foot while exercising the parts of the foot that are weak so that orthotics won't be needed after six or 12 weeks.

So what should people do before they buy shoes?

Jenkyn suggests taking the shoes home for a few days and testing out how they feel by walking or running in them often.

"It really comes down to that," he said. "If the shoe fits, then you wear it."